The fetlock is the most complicated high motion joint in the equine limb and is subject to huge loads and stresses during locomotion. Movement in the sagittal plane predominates and consists of flexion (during most of the swing phase of the stride) and extension (at the end of the swing and the stance phases). The fetlock is supported by an elastic suspensory apparatus including the flexor tendons, digital flexor ligament, cannon bone and long pastern bones. This is designed to store energy during flexion and release it as the foot lands. Injuries to the fetlock often result in loss of performance, and these may be due to damage to the bones (eg fractures), to the soft tissues or to the ligaments.
Fetlock injuries are a common problem in horses, especially those used for dressage, eventing and hunting. They can occur as the result of a single event such as a strike or fall, but more frequently they are the result of wear and tear and the accumulation of damage over time. This can be the case for conditions such as arthritis and sprains and ligament tears.
Ligament damage is one of the most common causes of lameness in the fetlock. Ligaments are bands of tough fibrous tissue that connect and stabilise the bones within a joint so that humans or animals can move and function normally. In horses, the main ligament that supports the fetlock is the suspensory ligament which runs from the carpal bones in the forelimbs or the tarsal bones in the hindlimbs to the fetlock joint and splits into two branches around the sesamoid bones at the back of the pasterns.
Injuries to the fetlock can be very painful and debilitating for the animal. Horses with fetlock injury tend to be very lame on a fetlock flexion test and will feel noticeably painful on palpation of the fetlock area. The fetlock will usually feel harder and thicker than normal and it may appear hot or swollen. X-rays and ultrasound will help to confirm diagnosis and assess the extent of injury.
For some horses with fetlock injuries, conservative management, pain relief and careful monitoring of the condition will allow them to return to full performance. However, for others, a fetlock arthrodesis will be needed to relieve pain and to prevent contralateral limb laminitis.
When bandaging a horses fetlock it is important to thoroughly clean the leg first to ensure that any wounds are free from dirt and contamination. Then, if there is a wound cover with an antiseptic such as betadine or chlorhexidine and wrap the wound in a clean and dry dressing such as melolin or a poultice wrap. Then apply an elastic/ vet wrap bandage to the fetlock, making sure that each turn overlaps the previous by half and wrap up to just above the fetlock joint. Once this is done, it is then a good idea to add some padding such as a cotton wool pad or melolin.